A local bicycle helmet 'law' in a Swedish municipality - the effects on helmet use.
D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000331:legislation & jurisprudence*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002947:Cities / Q000331:legislation & jurisprudence*; D005500:Follow-Up Studies; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D015397:Program Evaluation; D013548:Sweden